1. Field of the Invention
The present invention relates to a steering device for a vehicle in which both the front wheels and the rear wheels are steered by the steering device.
2. Description of Relevant Art
U.S. Pat. No. 4,295,657, issued on Oct. 20, 1981 to the present applicants, discloses a vehicle steering device wherein the front wheels and the rear wheels are steered by steering operation of the steering wheel. The steering device is constructed such that the rear wheels are steered in the same direction as that of the front wheels when the steering wheel is rotated a small angular extent, such as generally occurs during high speed driving of the vehicle, and in turn the rear wheels are steered in an opposite direction to that of the front wheels or the steering angle of the rear wheels is returned to zero or near to zero when the steering wheel is rotated a relatively large angular extent during low speed driving of the vehicle. In this manner, a difference of time in producing laterally directed forces in the front and rear wheels is eliminated, non-coincidence between a longitudinal direction of the vehicle and a tangential direction of a turning orbit is eliminated and at the same time a steering characteristic during high speed driving is improved, and steering operation of the steering wheel during low speed driving of the vehicle is improved or facilitated to such a degree as to be similar to that provided by a conventional type of vehicle in which only the front wheels are steered.
On the other hand, means for steering the rear wheels is assembled in a vehicle body in the foregoing arrangement, so that the steering means is required to be made as compact as possible in positional relation to other means similarly assembled in the vehicle body and other equipment, etc. Further, the steering means is applied with a rear wheel steering force as a load, so that a high mechanical strength of the means is required.
The present invention provides an improved steering device for vehicles which effectively meets the above-mentioned requirements.